Editing Openai/690f8ac2-4e38-8012-b650-1cba68fd0972 (section)

==  ==

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Boot from your Zorin USB installer again.

* When the live USB loads, open a terminal (Ctrl + Alt + T).
* Run: <syntaxhighlight lang="bash"> [ -d /sys/firmware/efi ] && echo "UEFI mode" || echo "Legacy mode" </syntaxhighlight>

If it says “Legacy mode”, Zorin was installed for MBR (not UEFI).

===  ===

Enter BIOS (F10 on boot):

* Reset BIOS to defaults (there’s usually an option for this).
* Then set: * Boot Mode → Legacy (if Zorin was installed in Legacy mode) * OR keep UEFI if Zorin was installed in UEFI mode * Disable Secure Boot (the 8460p doesn’t support it well anyway) * Check Boot Order → ensure “Zorin” or “Ubuntu” appears first (if UEFI) * Save changes and reboot

If you switch between Legacy/UEFI without reinstalling GRUB, it won’t boot.

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Boot again into the Zorin Live USB → Choose “Try Zorin”.

Open a terminal and run these commands to reinstall GRUB correctly for your chosen mode:

====  ====

<syntaxhighlight lang="bash">
sudo fdisk -l
# Find your Linux root partition, e.g. /dev/sda2
sudo mount /dev/sda2 /mnt
sudo grub-install --boot-directory=/mnt/boot /dev/sda
sudo update-grub

</syntaxhighlight>

====  ====

<syntaxhighlight lang="bash">
sudo fdisk -l
# Find EFI partition, usually /dev/sda1 (type EFI System)
sudo mount /dev/sda2 /mnt          # root
sudo mount /dev/sda1 /mnt/boot/efi # EFI
sudo grub-install --target=x86_64-efi --efi-directory=/mnt/boot/efi --bootloader-id=Zorin
sudo update-grub

</syntaxhighlight>

Then reboot:

<syntaxhighlight lang="bash">
sudo reboot

</syntaxhighlight>

===  ===

It’s likely BIOS can’t find a valid EFI entry.

From live USB:

<syntaxhighlight lang="bash">
sudo efibootmgr

</syntaxhighlight>

If no “Zorin” or “Ubuntu” entry appears, manually add one:

<syntaxhighlight lang="bash">
sudo efibootmgr --create --disk /dev/sda --part 1 --label "Zorin" --loader "\EFI\Zorin\grubx64.efi"

</syntaxhighlight>

Then reboot again.

===  ===

If the above doesn’t work and you don’t have important files yet:

* In BIOS, pick either UEFI or Legacy and stick with it.
* Reinstall Zorin OS from scratch using that same mode.

When booting the installer USB:

* If the boot menu says “UEFI: USB”, that means the installer is using UEFI mode.
* If it says just “USB”, that’s Legacy mode.

Install in whichever matches your BIOS setting.